MADRID (AP) — Spanish taxis are refusing to pick up passengers in a one-day strike against the increase in cars run by private companies offering cheaper, mobile ride-hailing services.

The stoppage, directed against the San Francisco-headquartered Uber and Madrid-based Cabify services, was called after a court recently allowed new licenses for these firms.

Unions say a law stipulating that there should be one private cab for every 30 taxis is being flouted.

Taxis converged on Madrid early Wednesday to take part in a midday protest from the city's main train station to a square near Parliament.

The strike left normally packed taxi ranks at airports and train stations empty.

Unions said they would provide free services for the elderly, pregnant women and people with physical mobility problems.